Sea turtles like all other turtle species exhibit internal fertilization. Sperm, from the male's penis, leaves the male and enters the female. Fertilization of the egg actually occurs in the oviducts of the female (some species can store the sperm for years at a time before fertilization takes place). All species of turtles lay eggs on land. They migrate long distances,thousands of miles, to lay their eggs on the beaches where they were born. After the eggs are laid and buried, the females abandons them never to see or raise her babies. :( The sex of the babies is determined by temperature from the sun heating the eggs until they hatch.